I was once asked to help a friend debug his server. Its mysql state was not loading properly, so I wrote an rsync line to back up all the mysql data as a safety

I was once asked to help a friend debug his server. Its mysql state was not loading properly, so I wrote an rsync line to back up all the mysql data as a safety step before debugging. A few seconds later, I realized I put a forward slash and a space in the wrong place and had managed to delete the entire directory. I felt like such an idiot. At least I haven't messed up an rsync command since!